Electronically-ballasted fluorescent lamps are often used as task lighting in office environments. Normally, in these applications the task lights are mounted in workstation furniture and are turned on by the user at the beginning of the day. The problem with this arrangement is that often the user forgets to turn the task lamps off at the end of the day, thus eliminating a large percentage of the energy savings from using a fluorescent lamp due to the lamp remaining on all night.
Previously, manufacturers have used mechanical or electronic timers in line between the power source and the light fixture in order to interrupt power to the light fixture after a specified time. Drawbacks of this approach include the significant added expense of a separate timing circuit. Additionally, such prior art solution also requires a significant volume to implement the circuitry required to interrupt the primary power to the fixture.
It would, therefore, be desirable to provide an electronic fluorescent lamp ballast with an integral timer feature that will allow the lamp to operate for a predetermined length of time and then shut the lamp off. It would be desirable for such timer feature to add only a marginal increase in cost and size of the lamp ballast.